1. Field of the Invention
The present invention is directed to an X-ray computed tomography apparatus of the type having a radiation detector composed of a row of detector elements.
2. Description of the Prior Art
In X-ray technology, it is known to employ X-ray detectors in which a scintillator converts X-rays incident thereon into visible light, this light then being converted by a photoelectrical converter into an electrical signal. An image of the examined subject can be created from the signals, for example. The positional resolution is generally not exact, since the optical propagation of the light with the scintillator leads to unsharpnesses. For example, if an X-ray quantum is incident at a point on the front of the scintillator, a smearing of the edges of this point can occur at the back of the scintillator (at which the light emerges) due to propagation of the light through the scintillator.
In digital radiography it is known to allocate a number of photoelectric converters as X-ray converters to a scintillation crystal in order to create corresponding electrical image signals. A desired image resolution is thereby achieved (U.S. Pat. No. 5,587,591; Nuclear Instruments and Methods in Physics Research, A 310, 1991, pages 471 to 474; German OS 195 24 858 A1; German PS 44 20 603). These known X-ray converters are not usable in computed tomography.